Hydrophobic, cationic polymers for treating construction aggregates

ABSTRACT

The present invention provides methods, admixture compositions for treating clay-bearing aggregates used for construction purposes, and aggregate compositions for construction purposes. The clay-bearing aggregates are treated with a cationic copolymer made from two and preferably three different monomer components. Cementitious compositions containing the treated aggregates are also described.

This application is a divisional based on Ser. No. 13/076,944 filed Mar.31, 2011, and issued as U.S. Pat. No. 9,034,968.

FIELD OF THE INVENTION

This invention relates to the treatment of sand aggregates used formaking construction materials, and more particularly to the mitigationof clay in construction aggregates using a cationic polymer.

BACKGROUND OF THE INVENTION

It is known that sand aggregates used in making construction materialssuch as concrete can contain clay materials that are detrimental to theconcrete and/or to the efficiency of plasticizers used in the concrete.

For example, U.S. Pat. Nos. 6,352,952 and 6,670,415, owned by the commonassignee hereof, Jardine et al. disclosed that certain clays, whichexpanded when in contact with water, were responsible for adverselyaffecting the dosage efficiency of “EO/PO” type superplasticizers (e.g.,which contained ethylene oxide and propylene oxide groups). Jardine etal. taught that clay-activity-modifying agents, such as organic cations(such as quaternary amines which have a strong affinity for cationicexchange with clay), could be introduced to the clay before, during, orafter water is introduced to the clay.

As another example, in U.S. Ser. No. 11,575,612 (Publ. No. 2007/0287794A1) and U.S. Ser. No. 11/575,607 (Publ. No. 2008/0060556 A1), Jacquet etal. disclosed compositions and methods for inerting clays in sandaggregates intended for use in preparing concrete. The compositionscould include monomers already containing a cationic quaternary aminefunctional group: such as diallyldialkyl ammonium, quaternized(meth)acrylates of dialkylaminoalkyl and (meth)acrylamides N-substitutedby a quaternized dialkylaminoalkyl. Particularly preferred were cationicpolymers obtained by polycondensation of dimethylamine andepichlorohydrin.

SUMMARY OF THE INVENTION

The present invention relates to the treatment of clay-bearingaggregates which are used in the preparation of concrete, mortar, andasphalt, and particularly to the use of a copolymer obtained throughpolymerization of certain monomer components, as will be moreparticularly described hereinafter.

The use of the copolymer can lead to improvement of properties in thecementitious compositions, such as workability without increasing waterdemand, and to reducing the effort needed to wash and dispose of theclay.

An exemplary method of the present invention for treating clay-bearingaggregates used in construction materials, comprises: introducing toclay-bearing sand aggregates, in an amount of 3% to 60% based on dryweight of said clay, a hydrophobically modified cationic copolymerobtained from the following monomer components:

(A) in an amount of 60-98 mol percent, a cationic polymer selected fromquaternized vinyl pyridine or other cationic monomer represented by thefollowing structures

wherein

R₁, R₂, and R₃ each independently represent hydrogen, —CH₃, or —COOH;

R₄, R₅, R₆, R₇, and R₈ each independently represent a C₁-C₄ alkyl group;

R₉ and R₁₀ each independently represent hydrogen or —CH₃;

Z₁ represents —O— or —NH—;

Y₁ represents —CH₂CH(OH)CH₂— or C₁-C₆ alkyl group; and

X represents a halide, pseudohalide, or sulfate;

(B) in an amount of 2-40 mol percent, a hydrophobic, essentiallywater-insoluble monomer selected from the group consisting of vinylacetate, acrylonitrile, methacrylonitrile, styrene and its derivatives,vinyl ethers of formula CH₂═CH—O—R₁₁ in which R₁₁ is a linear orbranched, saturated or unsaturated hydrocarbon radical from 1 to 12carbons, esters or amides of formula H₂C═CR₁₂—CO—Z₂—R₁₃ in which R₁₂ ishydrogen or C₁ to C₃ alkyl, Z₂ is —O— or —NH—, and R₁₃ is a linear orbranched, saturated or unsaturated hydrocarbon radicals having from 1 to18 carbons; and

(C) in an amount of 0-20 mol percent, a water-soluble monomer selectedfrom the group consisting of acrylamide, methacrylamide, alkyl ordialkyl acrylamide of methacrylamide, polyalkyleneoxide acrylate,polyalkyleneoxide methacrylate, and polyalkyleneoxide ether.

The present invention also provides an aggregate composition made fromthe foregoing method. The aggregate composition can be combined with acement binder to form a mortar or concrete, or combined with asphalticcomposition to provide asphalt compositions, and can be used generallyto form construction material compositions. The aggregate compositioncan alternatively be combined with one or more conventional admixturechemicals, such as a water reducer (e.g., superplasticizer) admixture;and may contain both a cement binder and water reducer.

The present invention also provides admixture compositions containingthe above-described copolymer for treating construction materialcompositions in combination with at least one chemical admixtureconventionally used for modifying hydratable mortar or concrete, such asone or more water reducing admixtures (e.g., a polycarboxylate combpolymer superplasticizer), or other conventional admixture oradmixtures, as will be further described in detail hereinafter.

Exemplary admixture compositions of the invention may be introduced toclay-bearing aggregates at or after the quarry or processing at anaggregates mine, or before or at the concrete mix plant, where theaggregates are combined with cement to provide mortar or concretecompositions.

Further exemplary embodiments of the invention comprise theabove-described hydrophobically modified cationic copolymer obtainedfrom monomer components (a) through (c) in combination with cement andaggregate (e.g., concrete).

Further advantages and features of the invention will be described infurther detail hereinafter.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The present invention pertains to method and compositions for treatingclays in sand aggregates intended for construction material purposesusing a hydrophobically-modified cationic polymer, as well as to cementand cementitious compositions, aggregate compositions, and concretecompositions containing the hydrophobically-modified cationic polymer.

The clays may be swelling clays of the 2:1 type (such as smectite typeclays) or also of type 1:1 (such as kaolinite) or of the 2:1:1 type(such as chlorite). The term “clays” has referred to aluminum and/ormagnesium silicates, including phyllosilicates having a lamellarstructure, but this term may also refer to clays not having suchstructures, such as amorphous clays. The present invention is notlimited to swelling clays, which have been seen to absorb EO/POsuperplasticizers as previously mentioned in the background, but alsoincludes the use of clays that may directly affect the properties ofconstruction materials whether in their wet or hardened state. Clayswhich are commonly found in sands include, for example, montmorillonite,illite, kaolinite, muscovite, and chlorite. These are also included inthe methods and compositions of the invention.

The clay-bearing sands which are treated by the method of the presentinvention may be used in cementitious materials, whether hydratable ornot, and such cementitious materials include concrete, mortar, andasphalt, which may be used in structural building and constructionapplications, roadways, foundations, civil engineering applications, aswell as in precast and prefabrication applications.

The term “sand” as used herein shall mean and refer to aggregateparticles usually used for construction materials such as concrete,mortar, and asphalt, and this typically involves granular particles ofaverage size between 0 and 8 mm, preferably between 2 and 6 mm. Sandaggregates may comprise calciferous, siliceous or siliceous limestoneminerals. Such sands may be natural sand (e.g., derived from glacial,alluvial, or marine deposits which are typically weathered such that theparticles have smooth surfaces) or may be of the “manufactured” typemade using mechanical crushers or grinding devices.

The construction materials in which the sand is used include hydratablecementitious compositions, such as mortar and concrete, and also mayinvolve asphalt compositions.

The term “cement” as used herein includes hydratable cement and Portlandcement which is produced by pulverizing clinker consisting of hydrauliccalcium silicates and one or more forms of calcium sulfate (e.g.,gypsum) as an interground additive. Typically, Portland cement iscombined with one or more supplemental cementitious materials, such asPortland cement, fly ash, granulated blast furnace slag, limestone,natural pozzolans, or mixtures thereof, and provided as a blend. Theterm “cementitious” refers to materials that comprise Portland cement orwhich otherwise function as a binder to hold together fine aggregates(e.g., sand), coarse aggregates (e.g., crushed gravel), or mixturesthereof.

The term “hydratable” is intended to refer to cement or cementitiousmaterials that are hardened by chemical interaction with water. Portlandcement clinker is a partially fused mass primarily composed ofhydratable calcium silicates. The calcium silicates are essentially amixture of tricalcium silicate (3CaO.SiO₂ “C₃S” in cement chemistsnotation) and dicalcium silicate (2CaO.SiO₂, “C₂S”) in which the formeris the dominant form, with lesser amounts of tricalcium aluminate(3CaO.Al₂O₃, “C₃A”) and tetracalcium aluminoferrite (4CaO.Al₂O₃.Fe₂O₃,“C₄AF”). See e.g., Dodson, Vance H., Concrete Admixtures (Van NostrandReinhold, New York N.Y. 1990), page 1.

The term “concrete” will be used herein generally to refer to ahydratable cementitious mixture comprising water, cement, sand, usuallya coarse aggregate such as crushed gravel, and optional chemicaladmixture(s).

As used herein, the term “copolymer” or “polymer” as used herein refersto compounds containing at least two different monomer components(designated as “A” and “B”) and optionally at least three differentmonomer components (further including optional monomer designated as“C”).

The copolymers of the invention are preferably made by conventionaladdition polymerization techniques such as radical polymerization.Preferably, the polymerization is conducted in aqueous solution using awater soluble free radical initiator including peroxides, such ashydrogen peroxide; persulfates, such as ammonium, sodium, or potassiumpersulfate; and water soluble azo initiators. Preferably, the molecularweight range of the copolymer is 1000-100,000; more preferably2,000-60,000; and most preferably the molecular weight range is5,000-50,000.

As summarized above, exemplary methods of the present invention involveintroducing the copolymer to clay-bearing aggregates at a quarry ormining plant, where the aggregate is manufactured or washed, or thecopolymer can be introduced to the clay-bearing aggregates at a concretemixing plant, where cement and aggregates are combined to make ahydratable mortar or concrete. In further exemplary methods, thecopolymer can also be added directly into the mortar or concrete,separately or together or in mixture with one or more conventionaladmixtures. Such conventional admixtures may include for example, ligninsulfonate, naphthalene sulfonate formaldehyde condensate (NSFC),melamine sulfonate formaldehyde condensate (MSFC), polycarboxylate combpolymers, gluconate, set retarders, set accelerators, defoamers, airentraining agents, surface active agents, or mixtures thereof.

Of the admixtures, so-called EO/PO type polymers, which have ethyleneoxide (“EO”) and/or propylene oxide (“PO”) groups and polycarboxylategroups, are preferred. Cement dispersants contemplated for use in theinvention include EO/PO polymers and EO/PO comb polymers, as describedfor example in U.S. Pat. Nos. 6,352,952 B1 and 6,670,415 B2 of Jardineet al., which mentioned the polymers taught in U.S. Pat. No. 5,393,343assigned to W. R. Grace & Co.-Conn. These polymers are available fromGrace under the trade name “ADVA®”. Another exemplary cement dispersantpolymer, also containing EO/PO groups, is obtained by polymerization ofmaleic anhydride and an ethylenically-polymerizable polyalkylene, astaught in U.S. Pat. No. 4,471,100. In addition, EO/PO-group-containingcement dispersant polymers are taught in U.S. Pat. No. 6,569,234 B2 andU.S. Pat. No. 5,661,206. The amount of such polycarboxylate cementdispersants used within concrete may be in accordance with conventionaluse (e.g., 0.05% to 0.25% based on weight of active polymer to weight ofcementitious material).

Thus, exemplary admixture compositions of the invention comprise: theabove-described copolymer and at least one polycarboxylate cementdispersant, which is preferably a polycarboxylate comb polymer having EOand PO groups, as described above.

As summarized above, an exemplary method of the present inventioncomprises: introducing to clay-bearing sand aggregates, in an amount of3% to 60% based on weight of clay treated, at least one copolymerobtained from monomer components (A), (B), and optionally (C), asfollows:

(A) in an amount of 60-98 mol percent, a cationic polymer selected fromquaternized vinyl pyridine or other cationic monomer represented by thefollowing structures

wherein

R₁, R₂, and R₃ each independently represent hydrogen, —CH₃, or —COOH;

R₄, R₅, R₆, R₇, and R₈ each independently represent a C₁-C₄ alkyl group;

R₉ and R₁₀ each independently represent hydrogen or —CH₃;

Z₁ represents —O— or —NH—;

Y₁ represents —CH₂CH(OH)CH₂— or C₁-C₆ alkyl group; and

X represents a halide, pseudohalide, or sulfate;

(B) in an amount of 2-40 mol percent, a hydrophobic, essentiallywater-insoluble monomer selected from the group consisting of vinylacetate, acrylonitrile, methacrylonitrile, styrene and its derivatives,vinyl ethers of formula CH₂═CH—O—R₁₁ in which R₁₁ is a linear orbranched, saturated or unsaturated hydrocarbon radical from 1 to 12carbons, esters or amides of formula H₂C═CR₁₂—CO—Z₂—R₁₃ in which R₁₂ ishydrogen or C₁ to C₃ alkyl, Z₂ is —O— or —NH—, and R₁₃ is a linear orbranched, saturated or unsaturated hydrocarbon radicals having from 1 to18 carbons; and

(C) in an amount of 0-20 mol percent, a water-soluble monomer selectedfrom the group consisting of acrylamide, methacrylamide, alkyl ordialkyl acrylamide of methacrylamide, polyalkyleneoxide acrylate,polyalkyleneoxide methacrylate, and polyalkyleneoxide ether.

Monomer component (A) can be chosen, for example, from a list includingdiallyl dimethyl ammonium chloride (DADMAC), 2-acryloyloxyethyltrimethyl ammonium chloride (AETAC), 2-methacryloyloxyethyl trimethylammonium chloride (METAC), acrylamidopropyl trimethyl ammonium chloride(APTMAC), methacrylamidopropyl trimethyl ammonium chloride (MPTMAC),quaternized N-vinylpyridine, quaternized 2-vinylpyridine, quaternized4-vinylpyridine.

As mentioned above regarding the first monomer component, “X” canrepresent a halide, pseudohalide, or a sulfate. Preferred halides arechloride and bromide. A pseudohalide is an anion that shares commonstructural and electronic features with the halides. Examples includecyanide, thiocyanate, azidothiocarbonate, selenocyanate, tellurocyanate,cyanate, azide, and their structural isomers.

Monomer component (B) can be chosen, for example, from acrylonitrile,methacrylonitrile, vinyl acetate, vinyl propionate, vinyl pivalate,vinyl butyrate, vinyl methacrylate, vinyl laurate, vinyl decanoate,styrene, α-methylstyrene, 3-methylstyrene, 4-methylstyrene,4-tert-butylstyrene, 2,4-dimethylstyrene, 2,4,6-trimethylstyrene, vinylethyl ether, vinyl propyl ether, vinyl butyl ether, vinyl isooctylether, vinyl 2-ethylhexyl ether, vinyl dodecyl ether, methyl(meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, hexyl(meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate,isodecyl (meth)acrylate, decyl (meth)acrylate, lauryl (meth)acrylate,dodecyl (meth)acrylate, tetradecyl (meth)acrylate, hexadecyl(meth)acrylate, octadecyl (meth)acrylate, N-dodecyl (meth)acrylamide,N-tert-octyl (meth)acrylamide, and N-1-hexyl (meth)acrylamide.

Monomer component (C) can be chosen, for example, from a group includingacrylamide, methacrylamide, N-methyl acrylamide, N-methylmethacrylamide, N-methylol acrylamide, N-methylol methacrylamide,N-isopropyl acrylamide, N,N-dimethyl acrylamide, N,N-dimethylmethacrylamide, N-vinyl pyrrolidone, 2-vinyl pyridine, 4-vinyl pyridine,N-vinyl pyridine, polyalkyleneoxide acrylate, polyalkyleneoxidemethacrylate, and polyalkyleneoxide ether.

In preferred embodiments of the invention, the molar ratio (A:B) ofmonomer component (A) to monomer component (B) is 0.60:0.40 to0.98:0.02; and, more preferably, the molar ratio (A:B) is 0.75:0.25 to0.95:0.05.

In other preferred embodiments, R₇ and R₈ of the above-describedcopolymer are —CH₃; and R₉ and R₁₀ of said copolymer are hydrogen.

In other preferred embodiments, Z₁ is oxygen and Y₁ is —CH₂CH₂—.

In still further embodiments, Z₁ is —NH— and Y₁ is —CH₂CH₂CH₂—.

In other embodiments of the invention, the above-described copolymer maycontain two or more monomer components which are both represented by thestructure of the first monomer (A). In other embodiments of theinvention, the copolymer may contain two or more monomer componentswhich are both represented by the structure of the second monomer (B).

In preferred embodiments of the invention, the copolymer has aBrookfield viscosity of 5 to 500 Centipoise (hereinafter “cps”) at 30 wt% aqueous solution at 20 degrees C.; and, more preferably, the copolymerhas a Brookfield viscosity of 10 to 200 cps at 30 wt % aqueous solutionat 20 degrees C.

Preferably, in methods and compositions of the invention, the amount ofthe copolymer introduced to the clay is 5% to 40%, and more preferably8% to 20% by weight, based on the weight of the clay being treated.

In one exemplary method of the invention, the sand treated by thecopolymer may then be combined with the components for making concrete,mortar, or asphalt. The present invention also relates to concrete,mortar, or asphalt containing the sand, clay, and above-describedcopolymer. The copolymer may be introduced to the sand by application tothe clay-containing aggregates at the quarry or mine, or at the concretemix plant where the aggregates are combined with cement to formhydratable mortar or concrete. The copolymer may be incorporated intothe aggregates at the concrete mix plant before the cement binder isadded, or into dry or wet mortar or concrete.

Thus, the invention also provides chemical admixtures containing thecopolymer described above as well as to aggregate compositions,cementitious compositions, and concrete compositions containing thehydrophobicaly modified cationic copolymer. It is contemplated thatconventional chemical admixtures may be used in combination with theabove-described copolymer in exemplary methods, admixture compositions,cementitious compositions, aggregate compositions, and concretecompositions of the invention. Such conventional admixtures may includefor example, lignin sulfonate, naphthalene sulfonate formaldehydecondensate (NSFC), melamine sulfonate formaldehyde condensate (MSFC),polycarboxylate polymer cement dispersants (such as the ethyleneoxide/propylene oxide (EO/PO) type described above), gluconate, setretarders, set accelerators, defoamers, air entraining agents, surfaceactive agents, or mixtures thereof.

Hence, the present invention also provides chemical admixturecompositions comprising the above-mentioned copolymer in combinationwith at least one conventional admixture, such as water reducingadmixtures (e.g., superplasticizers), defoamers, air entraining agents,surfactants, or mixtures thereof.

Exemplary cement and cementitious compositions, aggregate compositions,and concrete compositions of the invention contain thehydrophobically-modified cationic polymer derived from theaforementioned monomer components (A), (B), and optionally (C). Thus,exemplary cementitious compositions of the invention comprise at leastone hydratable cement binder in combination with the above-describedcopolymer for treating clay, and optionally aggregates containing claywhich requires the treatment described herein. Exemplary aggregatecompositions of the invention comprise sand aggregate in combinationwith the above-described hydrophobically-modified cationic polymer. Thesand aggregate may contain clay which requires treatment by theabove-described hydrophobically-modified cationic polymer, or it may beadded to sand aggregate that contains the clay which requires saidtreatment. Exemplary concrete compositions of the invention compriseaggregate containing the clay which requires the treatment, cement, andthe above-described hydrophobically-modified cationic polymer

While the invention is described herein using a limited number ofembodiments, these specific embodiments are not intended to limit thescope of the invention as otherwise described and claimed herein.Modification and variations from the described embodiments exist. Morespecifically, the following examples are given as a specificillustration of embodiments of the claimed invention. It should beunderstood that the invention is not limited to the specific details setforth in the examples. All parts and percentages in the examples, aswell as in the remainder of the specification, are by percentage weightunless otherwise specified.

Example 1

A diallyl dimethyl ammonium chloride (DADMAC) monomer aqueous solution(78.8 g, 65% active), n-propanol (40 ml), and distilled water (50 ml)were transferred into a 500 ml flask equipped with a condenser, amechanical stirrer, a thermocouple and a nitrogen inlet. The system waspurged with nitrogen gas to remove air, and the solution temperature wasincreased to 70 degrees C. Into the flask, three solutions, 55 g ofDADMAC monomer aqueous solution (65% active), a solution of 1 ml of3-mercaptopropionic acid, 11 g of 2-ethyhexyl acrylate (2-EHA, 11 g) in49 ml n-propanol, and 40 ml aqueous solution of ammonium persulfate(9.12 g) were added into the flask simultaneously over a period of 8hours. After addition, the reaction was held at 70° C. for 12 hours,then stopped by cooling to ambient temperature. The resulting materialis called Polymer A.

Using the same procedure, the following polymers were synthesized andsummarized in Table 1.

TABLE 1 Cationic polymers synthesized via procedure described in Example1 Hydrophobic DADMAC monomer Brookfield (wt %) Type^(a)) wt %Viscosity^(b)) Polymer A 78 2-EHA 22 48 Polymer B 89 2-EHA 11 21 PolymerC 74 t-BA 26 104  Polymer D 84 t-BA 16 65 Polymer E 92 t-BA 8 31 PolymerF 95 BMA 5 NA Polymer G 95 MMA 5 NA Reference-1 100 none 0 36^(a))2-EHA: 2-ethylhexyl acrylate; t-BA: tert-butyl acrylate; BMA,n-butyl methacrylate; MMA: methyl methacrylate. ^(b))Brookfieldviscosity was measured at 30 wt % solution, 20° C. using spindle S61 onmodel DV-II+ Brookfield viscometer.

Example 2

Another exemplary polymer (Polymer H) was synthesized as follows.Degassed water (50 ml) and n-propanol (50 ml) were charged into a 500 mlflask equipped with a condenser, a mechanical stirrer, a thermocoupleand a nitrogen inlet. The system was then purged with nitrogen gas andheated to 70° C. Into the flask, three solutions, 112.5 g of2-(methacryloyloxy)ethyl trimethylammonium chloride (METAC) monomeraqueous solution (80 wt % active), a solution of 1 ml of3-mercaptopropionic acid, 10 g of t-butyl acrylate (t-BA) in 50 mln-propanol, and 40 ml aqueous solution of ammonium persulfate (7.77 g)were added into the flask simultaneously over a period of 8 hours. Afteraddition, the reaction was hold at 70° C. for 12 hours then stopped bycooling to ambient temperature. The resulting material is called PolymerH.

Using the above descried procedure, the following polymers weresynthesized and summarized in Table 2.

TABLE 2 Cationic copolymer synthesized via procedure described inExample 2. METAC t-BA Brookfield (wt %) (wt %) Viscosity^(a)) Polymer H90 10 26 Polymer I 95 5 22 Reference-2 100 0 15 ^(a))Brookfieldviscosity was measured at 30 wt % solution, 20° C. using spindle S61 onmodel DV-II+ Brookfield viscometer.

Example 3

The effects of Polymers A, B, C, D and E on mortar workability weretested against the Reference-1, which is a homopolymer of DADMACsynthesized using the same procedure. The mortar test results areillustrated in Table 2. Mortar was prepared in the traditional mannerand was formulated as follows for 10 wt % treatment dosage: sand (1350g), cement (650 g), sodium montmorillonite (2.7 g), water (240 g), 1.95g of 40 wt % aqueous polycarboxylate superplasticizer (0.12% active byweight of cement), and 2.7 g of 10 wt % aqueous polymer solution of thisinvention. The aqueous polymer solution of this invention was added to apre-blended mixture of sodium montmorillonite and sand, followed byaddition of cement water and polycarboxylate superplastisizer. Theworkability of mortar was determined by measuring the slump and flow andwas calculated by the following equation, workability=slump+(flow 1+flow2)/2−100.

TABLE 3 Mortar workability test wt % on sodium w/c Workabilitymontmorillonite ratio (mm) Polymer A 10 0.37 215 Polymer B 10 0.37 181Polymer C 10 0.37 178 Polymer D 10 0.37 190 Polymer E 10 0.37 198Reference-1 10 0.37 178 Polymer A 25 0.36 208 Polymer B 25 0.36 227Polymer C 25 0.36 209 Polymer D 25 0.36 241 Polymer E 25 0.36 231Reference-1 25 0.36 190

As shown in Table 3, at equal w/c ratio and polymer dosage, thehydrophobically modified Polymers A, B, C, D and E exhibited higherworkability as compared to the unmodified polymer (Reference-1),indicating the effectiveness of these materials as clay mitigatingagents.

Example 4

The performance of the Polymers F and G were evaluated by mortar test.The test procedure of Example 3 was employed except that the workabilitywas measured as a function of time. The mortar workability performanceresults of mortars containing the polymers are summarized below in Table4.

TABLE 4 Mortar workability test Wt % on sodium Workability (mm)montmorillonite 4 min. 30 min. 60 min. Polymer F 6% 203 158 85 Polymer G6% 215 153 81 Reference-1 6% 206 138 60 Reference 0 140 30 20The results in Table 4 indicate that the polymer of this inventionclearly enhanced workability retention of the mortar.

Example 5

The performance of the Polymer I was evaluated by mortar test againstReference-2 following the test protocol described in Example 3 exceptthat the polymer of this invention was used at 15 weight percent basedon the weight of sodium montmorillonite. The results of mortarworkability performance is shown below in Table 5.

TABLE 5 Mortar Workability Test Workability (mm) 9 min. 30 min. 60 min.Polymer I 290 223 165 Reference-2 257 199 135As shown in Table 5, incorporation of hydrophobic monomers was seen toenhance workability of the mortar.

Example 6

The effects of the Polymers B and D on concrete slump were testedagainst Reference-1, which is a homopolymer of DADMAC.

Concrete was prepared in the traditional manner as follows: sand (1374lb/yd3), stone (1800 lb/yd3), cement X (Ordinary Portland Cement, 658lb/yd3), water (42 wt % based on cement), sodium montmorillonite (2.75lb/yd3), polycarboxylate superplasticizer (0.135% active by weight ofcement), and the polymers of this invention were added at 30 wt % activebased on the weight of sodium montmorillonite. Sand was blended withsodium montmorillonite and then mixed with the cationic polymer prior tomixing into the concrete. The performance of the sand containing thepolymers is shown below in Table 6.

TABLE 6 Concrete slump test Concrete slump (inch) at 9 min 30 min 50 minPolymer B 24.50 19.25 16.25 Polymer D 24.75 19.25 16.75 Reference-121.75 18.00 NAAs shown in Table 6, both Polymer B and D outperformed Reference-1 inproviding higher initial slump and higher slump over time.

Example 7

The effects of the Polymers B and D on concrete slump and slumpretention were also evaluated against Reference-1 using a differentcement. The test protocol of Example 6 was employed except that cement Xwas replaced with cement Y, also an OPC.

TABLE 7 Concrete slump test Concrete slump (inch) at Entry 9 min 30 min50 min Polymer B 25.25 22.25 19.25 Polymer D 26.00 21.25 16.75Reference-1 21.00 19.50 16.75

The higher slumps for both Polymer B and D shown in Table 7 confirm thatthe polymers of this invention performed as effective clay mitigatingagents.

Example 8

The effects of the Polymer H on concrete slump were tested againstReference-2, which is a homopolymer of METAC, using the test protocol ofExample 6 and OPC cement Z. The concrete slump test results aretabulated in Table 8.

TABLE 8 Concrete slump test Concrete slump (inch) at 9 min 30 min 50 minPolymer H 24.25 19.25 18.00 Reference-2 24.75 17.75 16.50

As shown in Table 8, although the initial slumps of Polymer H andReference-2 are comparable, Polymer G is capable of maintaining a higherslump than Reference-2 over time, indicating its effectiveness as a claymitigating polymer.

The foregoing examples and embodiments were presented for illustrativepurposes only and not intended to limit the scope of the invention.

It is claimed:
 1. A composition comprising: (i) a water-reducer formodifying hydratable mortar or concrete; and (ii) at least one copolymerobtained from monomer components as follows: (A) a cationic monomerrepresented by one of the following structures

wherein R₁, R₂, and R₃ each independently represent hydrogen, —CH₃, or—COOH; R₄, R₅, R₆, R₇, and R₈ each independently represent a C₁-C₄ alkylgroup; R₉ and R₁₀ each independently represent hydrogen or —CH₃; Z₁represents —O— or —NH—; Y₁ represents —CH₂CH(OH)CH₂— or C₁-C₆ alkylgroup; and X represents a halide, pseudohalide, or sulfate; and (B) ahydrophobic, essentially water-insoluble monomer selected from the groupconsisting of vinyl acetate, acrylonitrile, styrene and its derivatives,vinyl ether of formula CH₂═CH—O—R₁₁ in which R₁₁ is a group selectedfrom a linear or branched, saturated or unsaturated, hydrocarbon radicalmoiety having from 1 to 6 carbons, and ester or amide represented by theformula H₂C═CR₁₂—CO—Z₂—R₁₃ in which R₁₂ is a hydrogen or C₁ to C₃ alkylgroup, Z₂ is —O— or —NH—, and R₁₃ is a linear or branched, saturated orunsaturated hydrocarbon radical moiety having from 1 to 8 carbons;wherein said water reducer is selected from the group consisting oflignin sulfonate, naphthalene sulfonate formaldehyde condensate (NSFC),melamine sulfonate formaldehyde condensate (MSFC), and mixture thereof.2. The composition of claim 1 wherein said copolymer has a molecularweight of 1,000-100,000.
 3. The composition of claim 1, wherein saidcopolymer has a molecular weight of 2,000-60,000.
 4. The composition ofclaim 1, wherein said copolymer has a molecular weight of 5,000-50,000.5. The composition of claim 1 wherein the molar ratio (A:B) of saidfirst monomer component (A) to said second monomer component (B) is0.75:0.25 to 0.98:0.02.
 6. The composition of claim 1 wherein the molarratio (A:B) of said first monomer component (A) to said second monomercomponent (B) is 0.80:0.20 to 0.95:0.05.
 7. The composition of claim 1wherein each of R₇ and R₈ are —CH₃ groups, and each of R₉ and R₁₀ arehydrogen.
 8. The composition of claim 1 wherein Z₁ is oxygen and Y₁ is—CH₂CH₂—.
 9. The composition of claim 1 wherein Z₁ is —NH— and Y₁ is—CH₂CH₂CH₂—.
 10. The composition of claim 1 wherein said copolymer hastwo or more monomer components which are represented by said structuresof said monomer component (A).
 11. The composition of claim 1 whereinsaid copolymer has two or more monomer components which are representedby said structures of said monomer component (B).
 12. The composition ofclaim 1 wherein said copolymer further comprises a monomer selected fromthe group consisting of acrylamide, methacrylamide, alkyl acrylamide,dialkyl acrylamide, alkyl methacrylamide, dialkyl methacrylamide,polyalkyleneoxide acrylate, polyalkyleneoxide methacrylate, andpolyalkyleneoxide ether.
 13. The composition of claim 1 furthercomprising gluconate, EO/PO polymer, or mixture thereof.
 14. Thecomposition of claim 1 further comprising a cement binder.
 15. Thecomposition of claim 1 further comprising aggregates.
 16. Thecomposition of claim 14 further comprising aggregates.
 17. Thecomposition of claim 1 further comprising an admixture chosen from setretarders, set accelerators, defoamers, air entraining agents, surfaceactive agents, or mixtures thereof.
 18. A concrete compositioncomprising the composition of claim
 1. 19. An aggregate compositioncomprising the composition of claim
 1. 20. The aggregate composition of19 further comprising a gluconate and EO/PO polymer.